How Sub-Slab Vapor Mitigation Systems Work
Sub-slab systems function similarly to soil vapor extraction or active landfill gas systems. The key difference: the building slab itself acts as the cap. System components typically include:
- Horizontal and verticle extraction piping installed beneath the floor slab
- Appropriately sized blowers to generate sub-slab negative pressure
- Optional passive vents or treatment units for off-gas management
In buildings with gravel bedding beneath the slab, vapor collection may be possible without piping—the gravel acts as a built-in vapor conduit. Each system is customized based on slab design, soil conditions, and vapor source location.
Expert Implementation in Operational Environments
AST has installed sub-slab systems in a variety of active commercial and industrial settings, often under tight schedules and restrictive access conditions. Field techniques include:
- Night and off-shift installation work
- Use of temporary dust and vapor barriers
- Horizontal and angled drilling beneath slabs and foundations
- Relocation of equipment or infrastructure to maintain operations
These projects benefit from AST’s broader experience with systems like SVE, multi-phase extraction, and groundwater recovery—ensuring seamless integration of sub-slab vapor mitigation with larger remedial strategies.
